ldap_provisioning

Changelog:
 * Changed default pending accounts rows per page limit to 50;
 * Ensured that ldap search is not triggered for the drupal only account;
 * Integrated bulk accounts creation with the Batch API to avoid timeouts;
 * Ensured that the roles array is set. This is to avoid errors in the rules module (currently unused);
 * Fixed quotes escaping in the cvs import;